Code Kept Secret for Years Reveals Its Flaw–A Backdoor

>TETRA encryption algorithms use 80-bit keys ... but TEA1 has a feature that reduces its key to just 32 bits

https://en.wikipedia.org/wiki/Export_of_cryptography_from_th...

>Later provision was added to allow export of 56-bit encryption if the exporter promised to add "key recovery" backdoors by the end of 1998.

First SSL crippled to 40-bit RC2/RC4

First 802.11 wireless protocol WEP "64" key length shortened to 40 bits

https://en.wikipedia.org/wiki/A5/1 vs https://en.wikipedia.org/wiki/A5/2

>to allow the British secret service to eavesdrop more easily. The British proposed a key length of 48 bits, while the West Germans wanted stronger encryption to protect against East German spying, so the compromise became a key length of 54 bits

>Documents leaked by Edward Snowden in 2013 state that the NSA "can process encrypted A5/1"

Guess we can add Tetra to the list.

Terrestrial Trunked Radio (TETRA) – (Trans-European Trunked Radio) : https://en.wikipedia.org/wiki/Terrestrial_Trunked_Radio